Abiotic and Biotic Factors

Abiotic Factors

WindStrong winds make branches and trees fall, beginning the decomposition process that returns nutrients captured in plants back to the soil. However, less noticeable winds are no less important. White trilliums, a small plant, rely on winds to spread pollen, fertilizing nearby plants. But winds also pick up particles from exposed soil, spreading not only dirt, but any bacteria or fungal microorganisms that may be present in the soil. Long periods of strong winds can even be responsible for spreading disease through a forest. WaterWater is nonliving, and plants and animals rely on it for survival. Whether falling on the forest plants as rain or drank by animals from a pond or slow-moving stream, life in the forest would not be able to survive without it. Standing and slow-moving water is also an entire habitat to a number of microorganisms, such as algae. When the temperature and chemical makeup of the water is right, this can encourage the growth of organisms like algae that can potentially throw off the existing balance of the ecosystem. Large algae blooms can cover an area, blocking sunlight from plants and animals below, stifling growth. Rainfall is also a critical factor in the deciduous forest; the constant precipitation keeps soil moist without being wet, making it one of the most fertile biomes. TemperatureWarm spring months ease the plants and animals back to life, encouraging animal reproduction with the development of new leaves and plants. The warmer summer months allow these animals long enough to raise their young, often allowing them to set off on their own prepared to fend for themselves by the fall. As the temperature starts to drop, the trees of the deciduous forest lose their leaves and go into a state of hibernation. This temperature cue is critical for the animals as well, some of whom begin storing food for the winter months while others gorge themselves in preparation for hibernation. The long winter months mean a struggle for survival during the long period when the deciduous forest is snow-covered. Plants and animals alike structure their habits and life cycles around this time. SunlightAll plants need sunlight to survive, and it is this basic building block of life that has formed much of the structure of the deciduous forest. Trees are encouraged to grow tall; the taller the trees, the more sunlight is available to the leaves of the canopy. Beneath these tall, established trees are a shorter layer, often close to the ground. These ferns and shrublike bushes tend to be varieties that thrive in shady conditions, as they have to survive on what sunlight makes it through the trees. In turn, many of the herbivores in the forest are species that have adapted to live on these smaller plants.

Biotic Factors

PathogensMany organisms are effected by pathogens in the forest. For example, rabies is always a concern in the park. This disease causes inflammation of the brain, which makes the victims hallucinate and often become violent. It is highly contagious through saliva (e.g. being bitten by an infected animal).

ParasitesParasites also negatively affect organisms in the park. One of the most well know parasites in this area is the tick, a small arachnid that attaches to the skin of an organism and drinks its blood. Deer ticks in particular are known to carry diseases such as Lyme disease and Rocky Mountain fever.

CompetitionOrganisms in the park compete for resources such as food, water, or mates. For example, male deer compete with each other for mates in the springtime. Competition can effect where an organism lives and what time of day it comes out.

PredationAny organism that does not produce its own food must obtain energy by feeding on another organism. For example, insects eat grass, frogs eat insects, and owls eat frogs. Predation has caused many forest animals to take on special adaptations to help them escape predators or catch prey more easily.